Staten Island Advance/John AnneseThe door remains charred at a Vanderbilt apartment building where the incident occurred.

STATEN ISLAND, N.Y. -- He took matters into his own hands.

A 24-year-old Stapleton man was so enraged by the mother of his unborn child, police say, that he smeared his own excrement on her apartment door in Clifton and lit it ablaze — all while she, her two young children, and two other people were trapped inside.

Rasheen (Illuminati) Harrison, of Hill Street, now faces arson and other charges in connection with the bizarre Sunday incident.

Harrison’s rampage began shortly before 5:30 a.m., police allege — he stripped naked inside the elevator of his ex-girlfriend’s apartment building on the 300 block of Vanderbilt Avenue, then defecated, according to authorities.

He then went to the woman’s sixth-floor apartment, wiped the excrement on the door, and lit his clothes and the door on fire, authorities allege.

"I’m going to set your house on fire and this whole building down with you in it," he screamed, capping off the remark with a string of expletives, according to court papers.

The woman and her two young children were inside at the time and couldn’t leave, since the door and the doorknob were hot to touch, police allege. She’s also six months pregnant with his child, according to a law enforcement source

"I’m the devil!" Harrison was heard yelling as he knocked on a neighbor’s door early Sunday morning.

Mrs. Shepherd said her husband, Dave, was home at the time. Harrison knocked on the door, made the devil remarks, and said the apartment was on fire, so her husband called 911, she said.

When firefighters and police arrived, Harrison was naked and still had the evidence on his hands, the source said.

"Yeah, I did it," he allegedly told police. "She stole my cell phone. I had a yellow lighter. I set it on fire."

Later, Harrison was taken to a cell in the 120th Precinct stationhouse in St. George where, a law enforcement source said, he defecated a second time.

The charred remains of the incident were still visible on the floor by the burnt metal door this afternoon. No one answered the door to comment.

Harrison is charged with second-degree arson, third- and fourth-degree criminal mischief, five counts each of second-degree reckless endangerment and third-degree menacing, and two counts of endangering the welfare of a child, said Peter N. Spencer, a spokesman for District Attorney Daniel Donovan.